Assuming that you equally like a car with or without stripes, then the value of the car is based on supply of buyers and demand. In general, for model years 01 and 02, for most colors, monotone is the more rare vehicle (for ACR's). In some color combinations, one quarter to one third of the vehicle run had monotone colors, rather than stripes. For GTS vehicles, the majority WERE made as monotone. As Tim721 put above, it is also my opinion that a majority of the consuming public do NOT like stripes, although many here disagree. Moreover, as Randy discussed above, for many individuals, stripes are a down right deal breaker. You will find, as you look around, that lighter stripes can show defects (especially on darker finished cars). If that stripe is not perfect, the eye goes immediately to the defect. It detracts from the overall look of the car and, consequently, the owner has a more difficult time selling because the car is not "perfect" in the eyes of the buyer. People are not going to want to buy a car with an immediate negative visual impact or something they will have to touch up.
Monotone cars do have a slight advantage in that respect. You will see tons of striped vehicles out there with rock damage on the stripe, making a bad presentation. It is harder to notice this damage on a monotone. Be warned, however, in that if you are looking for a specific model year, especially an 01 or 02 ACR without stripes, you may have to wait a long time to purchase that vehicle. Take for instance, sapphire blue ACR's without stripes. Only one model year made. Factoring in the limited amount of monotone cars available (about mid 20s), cars getting wrecked and abused, and cars getting shipped out of the country, there are very very few out there for serious consideration. Some colors are just very very hard to find. It is all in what you want, that is true, but the laws of supply and demand rule here as you note resale price in your question. For late model ACR cars (for a majority of the colors), in my opinion, the stripes detract from the value.